The Intercensal Population Estimates Program

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The Intercensal Population Estimates Program
Jason Devine U.S. Census Bureau Prepared for
the 2003 Pennsylvania State Data Center Data User
Conference September 18, 2003

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Overview

• Pennsylvania Estimates Data
• Estimates Program Overview
• Schedule
• Methodology
• Website
• Evaluation
• Future Directions

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Pennsylvania Overview

• Ranked 6th in Overall Population Size on July 1,
• 2002
• Ranked 27th in Numeric and 46th in Percent
  Change
• between Census 2000 and July 1, 2002
• Was estimated to have 12,335,091 people on
• July 1, 2002
• This is an increase of 54,037 people since
• Census 2000

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Pennsylvania Overview
The Increase in population was mainly due to
natural increase. There were more births than
deaths and only small gains from migration
between April 1, 2000 and July 1, 2002
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County Population Numeric Change 2000-2002
Philadelphia and Allegheny were the only counties
over 500,000 to lose population from 2000
2002. Birth, Death, and Migration Data are also
available at the county level.
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City Population Percent Change 2000-2002
Bethlehem was the only city over 50,000 that
gained population between 2000 and 2002
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Population Estimates Projections
Organizational Structure
Population Division Chief John Long
Population Estimates and Projections ADC Signe
Wetrogan [phone]
Population Analysis and Evaluation Branch Gregg
Robinson [phone]
Population Estimates Branch Mike
Batutis [phone]
Population Projections Branch Gregory
Spencer [phone]
Administrative Records and Methodology
Research Branch Rodger Johnson [phone]
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Intercensal Estimates Program
Required under Title 13, Section 181 During the
intervals between each census of populationthe
Secretary, to the extent feasible, should
annually produce and publish for each state,
county, and local unit of general purpose
government which has a population of 50,000 or
more, current data on total population and
population characteristics, and to the extent
feasible, shall biennially produce and publish
for other local units of general purpose
government current data on total population.
If we cannot produce these estimates, a report
by the Secretary of Commerce to the President of
the Senate and Speaker of the House is required
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Population Estimates Products

• National population estimates
• Monthly by age, sex, race, and Hispanic Origin
• State population estimates
• Annually by age, sex, race, and Hispanic Origin
• County population estimates
• Annually by age, sex, race, and Hispanic Origin
• Functioning governmental units
• Annually by total population for 39,000
  governmental entities

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Population Projections Products

• National population projections
• by age, sex, race, and Hispanic Origin
• State population projections
• by age, sex, race, and Hispanic Origin

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Uses of Population Estimates

• Allocation of over 200 billion in federal
  funds
• Controls for federal surveys
• Current Population Survey
• American Community Survey
• Denominators for statistical rates
• Birth and death rates
• Per capita income
• Program planning
• Location of public and private services

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The Federal-State Cooperative Program for
Population Estimates
In 1973 the Federal-State Cooperative Program for
Population Estimates was formalized. The FSCPE
was formed to

• Promote cooperation between states and the
  Census Bureau
• Prepare a set of consistent state, county and
  subcounty estimates
• Improve and advance estimates methodology
• Enhance the recognition of local demographic
  work

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When Are the Population Estimates Released

• Estimates
• National and State population totals
• December 2003 (estimates for July 2003)
• County population totals
• April/May 2004 (estimates for July 2003)
• National demographic detail
• March/April 2004 (estimates for July 2003)
• Subcounty population totals
• July/August 2004 (estimates for July 2003)

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When Are the Population Estimates Released

• State and County demographic detail
• July/August 2004 (estimates for July 2003)
• State and County housing units
• June/July 2004 (estimates for July 2003)
• Projections
• National Projections
• Revised projections by November 2004

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Methodology
National, state, and county levels Component
method P2 P1 B - D NM
Subcounty level Distributive housing unit
method County population distributed to
subcounty parts based on updated estimates of
housing units
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A Quick Look at the Website
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A Quick Look at the Website
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A Quick Look at the Website
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Estimates Evaluation Results
U.S. 2000
Pennsylvania 2000
PERCENT DIFFERENCE

• State/National Total Population
• State/National Housing Unit Estimates
• County Total Population
• County Housing Unit Estimates
• Subcounty Total Population

• -2.4 -2.4
• 0.9 -0.3
• 2.2 3.3
• 1.8 4.6
• 7.8 12.4

MEAN ABSOLUTE PERCENT DIFFERENCE (MAPE)
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Accuracy of Pennsylvanias Population Estimates
Census 2000
Intercensal Estimates
-2.4
1990 Based Estimates
1990 Census
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Accuracy of Subcounty Estimates
Census 2000
1990 Census
-0.4
1990 Based Estimates
Census 2000
1990 Census
6.2
1990 Based Estimates
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Accuracy of Subcounty Estimates
1990 Census
Census 2000
-0.4
1990 Based Estimates
Census 2000
1990 Census
6.2
1990 Based Estimates
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Future Directions

• Improve Dissemination of Estimates
• Introduce Methodological Enhancements
• Maintain Timeliness of Estimates Releases

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Improve Dissemination of Estimates

• Improve design of estimates web releases
• Meet needs of data viewers and data crunchers
• Use the American Fact Finder where appropriate

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Introduce Methodological Enhancements

• Improve estimates of International Migration
• Use latest boundaries in subcounty estimates
• Incorporate Count Question Resolution updates
  into the estimates base file
• Increase involvement of FSCPE and SDC
• Integrate ACS and Special Census Results with
  estimates

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Intercensal Population Estimates Program
Jason Devine jason.e.devine_at_census.gov (301)763-60
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